Strong-coupling corrections to ground-state properties of a superfluid Fermi gas
Strong-coupling corrections to ground-state properties of a superfluid Fermi gas
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DOI：
10.1103/physreva.95.043625
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发表时间：
2017-04
影响因子：
2.9
通讯作者：
H. Tajima;P. Wyk;R. Hanai;D. Kagamihara;D. Inotani;M. Horikoshi;Y. Ohashi
中科院分区：
文献类型：
--
作者：
H. Tajima;P. Wyk;R. Hanai;D. Kagamihara;D. Inotani;M. Horikoshi;Y. Ohashi
我们从理论上提出了一种经济且方便的方法来研究强相互作用超流费米气体的基态性质。我们的策略是，复杂的强耦合计算仅用于评估对化学势 $\mu$ 的量子涨落校正。然后，在没有任何进一步的强耦合计算的情况下，我们通过使用精确的热力学恒等式，在不损失准确性的情况下，根据计算出的 $\mu$ 计算压缩率、声速、内能、压力和 Tan 接触。使用最近对超流体 $^6$Li 费米气体中 $\mu$ 的精确测量，我们表明扩展的 $T$ 矩阵近似（ETMA）适合我们的目的，特别是在 BCS 酉体系中，我们的结果表明多体校正由超流体涨落主导。由于在冷费米气体物理学中精确确定物理量并不总是容易的，因此我们的方法将大大减少理解这种强相互作用费米系统的基态特性的实验和理论工作。
We theoretically present an economical and convenient way to study ground-state properties of a strongly interacting superfluid Fermi gas. Our strategy is that complicated strong-coupling calculations are used only to evaluate quantum fluctuation corrections to the chemical potential $\mu$. Then, without any further strong-coupling calculations, we calculate the compressibility, sound velocity, internal energy, pressure, and Tan's contact, from the calculated $\mu$ without loss of accuracy, by using exact thermodynamic identities. Using a recent precise measurement of $\mu$ in a superfluid $^6$Li Fermi gas, we show that an extended $T$-matrix approximation (ETMA) is suitable for our purpose, especially in the BCS-unitary regime, where our results indicate that many-body corrections are dominated by superfluid fluctuations. Since precise determinations of physical quantities are not always easy in cold Fermi gas physics, our approach would greatly reduce experimental and theoretical efforts toward the understanding of ground-state properties of this strongly interacting Fermi system.